Harvard Medical School Department of Otolaryngology
More than half of the population will see a doctor at some point in their lives with symptoms related to the vestibular system (e.g., dizziness, vertigo, imbalance, blurred vision). Vestibular disorders are often debilitating and even life-threatening when falls result. Researchers focusing in the area of the vestibular system seek to improve diagnostic techniques and to develop and refine treatments for patients suffering from vestibular disorders.
Collaboration between scientists, engineers and physicians at Massachusetts Eye and Ear/Harvard Medical School has led to the development of balance aids for patients suffering imbalance, as well as vestibular implants for patients who have lost inner-ear function. Additionally, researchers are dedicated to overcoming the limitations of clinical vestibular testing and improving diagnoses for the large number of patients whose diagnoses cannot be confirmed by testing.
The work of our vestibular researchers largely takes place in our vestibular laboratories:
Jenks Vestibular Physiology Laboratory
Under the direction of Daniel M. Merfeld, Ph.D., scientists in the Jenks Vestibular Physiology Laboratory study vestibular function using various behavioral measures, including assays of balance, perception and the vestibulo-ocular reflex (VOR). They engage in both basic science and translational research, using dynamic systems models to help gain insight into the complexities of multi-sensory integration involved in our sense of spatial orientation.
Historically, the Jenks Vestibular Physiology Laboratory was the first to study vestibular implants to treat patients suffering from severe bilateral vestibular loss. Investigators also have a number of patents that have been licensed by commercial entities intent on bringing this device to the market in the near future. They continue to maintain significant research interests in this area.
Presently, much of the translational effort focuses on the development of more sensitive and more specific diagnostic tests of vestibular function for patients suffering from dizziness, imbalance, or vertigo. This is significant because a substantial fraction of patients suffering from dizziness, vertigo, and/or imbalance are difficult to diagnose using existing tests that focus on measurements of reflexive responses like the vestibulo-ocular reflex (VOR).
Much of the basic science effort focuses on human spatial orientation and perception, with a strong interest in understanding the limits of human performance via the measurement of thresholds. We also perform basic science studies focusing on understanding how the brain combines cues from many different sensory systems (sometimes referred to as multi-sensory integration) with a keen interest in how the brain processes ambiguous sensory cues, like those provided by the otolith organs that provide both gravitational and acceleration cues.
Jenks Vestibular Diagnostic Laboratory
Under the direction of Conrad Wall, III, Ph.D., the Jenks Vestibular Diagnostic Laboratory offers a proprietary approach to clinical vestibular testing to assess vestibular function in the inner ear. There are four main tests offered in the laboratory, including: electonystagmogram (ENG), rotary chair testing, visual-vestibular interaction, and posturography (EquiTest). Medical Director Richard F. Lewis, M.D. interprets the results of the full test battery for patients and their referring physicians.
In addition to its clinical vestibular testing role, the laboratory’s research objectives include:
- Application of multivariate statistics to increase the sensitivity and specificity of clinical tests
- Translational research in vestibular prostheses
With collaborators in Geneva, investigators in the Jenks Vestibular Diagnostic Laboratory have shown that acute simulation of the human posterior ampullary nerve produces robust eye movements, thus supporting the development of vestibular implants. Investigators have worked with many collaborators to show that a non-invasive balance aid that provides subjects with feedback about the tilt of their body from the vertical can help them stand and walk more securely
The drawing on this page was published in "Spatial Orientation and the Vestibular System." Merfeld, Daniel M. Sensation & Perception. 3rd ed. Sunderland, MA: Sinauer Associates, 2012.
Vestibular InvestigatorsMichael S. Cohen, M.D.
Mitchell L. Day, Ph.D.
John J. Guinan, Jr., Ph.D.
Barbara S. Herrmann, Ph.D.
Faisal Karmali, Ph.D.
Richard F. Lewis, M.D.
Daniel M. Merfeld, Ph.D.
Adrian J. Priesol, M.D.
Steven D. Rauch, M.D.
Conrad Wall, III, Ph.D.
D. Bradley Welling, M.D., Ph.D., FACS
Gregory T. Whitman, M.D.